Acta Geodaetica et Cartographica Sinica ›› 2025, Vol. 54 ›› Issue (6): 982-994.doi: 10.11947/j.AGCS.2025.20240451

• Geodesy and Navigation • Previous Articles     Next Articles

A method for satellite ultra-rapid orbit and clock offset estimation based on the prior information of the GNSS clock parameters

Qianxin WANG1(), Chao HU2,3(), Tong CHENG1   

  1. 1.School of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
    2.School of Spatial Information and Geomatics Engineering, Anhui University of Science and Technology, Huainan 232001, China
    3.State Key Laboratory of Spatial Datum, Xi'an 710054, China
  • Received:2024-11-05 Revised:2025-05-12 Online:2025-07-14 Published:2025-07-14
  • Contact: Chao HU E-mail:wqx@cumt.edu.cn;chaohu2014gnss@163.com
  • About author:WANG Qianxin (1980—), male, PhD, professor, majors in satellite geodesy data processing. E-mail: wqx@cumt.edu.cn
  • Supported by:
    The National Key Research and Development Program of China(2020YFA0713502);The National Natural Science Foundation of China(42404015);Guangxi Science and Technology Base and Talent Special Project(桂科AD25069103)

Abstract:

GNSS ultra-rapid orbit and clock products are widely used in the area of real-time and near-real-time fast location-based services. However, due to the restriction of time-consuming and observations quality in the parameters estimation, the correlation between orbit and clock offset parameters in ultra-rapid determination is not considered. In addition, the merits of satellite onboard clock information is ignored. Therefore, in this research, an improved ultra-rapid orbit and clock estimation method is proposed based on the prior constraint on the GNSS clock parameters. First, the time-difference carrier phase algorithm is used to epoch-wisely update the satellite clock offset by fixing satellite orbit. Second, the short-term prediction model of clock offset is constructed to extract the prior information and model the satellite onboard atomic clock parameters. Third, the augmented model of ultra-rapid orbit and clock offset is constructed by the constraint of satellite onboard clock parameters in orbit determination equation. According to the experiment results, it is indicated that the significant correlation among orbit and clock offset parameters is presented, in which the accuracy of ultra-rapid clock offset can be improved with 30.9%~50.7%, compared with the traditional ultra-rapid clock products by fixing the orbit parameters. Meanwhile, the millimeter-level and at least 32.9% for orbit and clock offset accuracy improvements can be obtained by the prior constraint on clock parameters. Additionally, the performances of static PPP solution are respectively improved with 9.9%, 16.9% and 9.3% for E, N and U directions, compared with the traditional ultra-rapid orbit and clock products. Therefore, the proposed GNSS satellite orbit and clock offset method can effectively improve the performances of ultra-rapid products, which will further provide supporting for the high-quality PNT services.

Key words: GNSS, ultra-rapid satellite clock offset, prior information, orbit and clock offset parameters, parameters estimation

CLC Number: